2. WordPress
Through admin interface: Log in your administration page. Click on Manage > Export > Dowload Export file. Thats all. Yes you read correct, thats all, no more steps to take (:
Backup with phpMyAdmin: phpMyAdmin (most of hosting companies provides it) is a web based application, that lets you to easily handle your databases. This tool also allows you to edit data in the database.
With phpMyAdmin, you can export entire database, or only the tables. If you are going to create your database manualy while restoring it back, then export only tables. In that case you will need to select your database from the dropdown menu from the left column on main page (or simply click on databases link in main frame). After selecting your database click on export link for exporting the tables. You will be presented with the export screen. Make your settings same as in this picture.
Once you click on GO, you immediately will be prompted to save back up file to your local computer.